Any discussion of the background art throughout the specification should in no way be considered as an admission that such art is widely known or forms part of common general knowledge in the field.
Electric vehicles have been available for many decades and make use of one or more electric motors to provide locomotive drive for the vehicle. In more recent times this form of vehicle is becoming increasingly more viable as cars for private and commercial use. Electric vehicles offer many advantages over vehicles with an internal combustion engine (ICE) and hybrid ICE/electric motor vehicles. However, the major disadvantage or drawback of electric vehicles remains: the range that is available between recharging is relatively short, and the charging time, particularly to obtain a full charge, is long relative to the refuelling time for a car with an ICE.
To encourage the sale and use of electric vehicles at least one electric vehicle manufacturer is making efforts to have purpose-built rapid charging stations constructed in a number of different locations in different countries. This however remains a very expensive infrastructure-based solution that will take considerable time to meaningfully deploy.
The requirement for purpose-built charging stations and other infrastructure to reduce the duration of the recharge time for electric vehicles arises partly from the installation within such vehicles of recharging circuitry that is only capable of accommodating relatively low power levels. One factor contributing to the inclusion of this lower power circuitry in the vehicles is to reduce the cost of manufacture of the vehicles. However, other motivations are to reduce the weight and size of the vehicles. For high power components, and the need to keep those components within acceptable operating temperature ranges, consumes considerable space and adds considerable weight, both of which diminish vehicle performance and range. Additionally, the weight of the recharging components can be considered dead weight whilst driving, as it is only used when the vehicle is stationary and not operating.
One partial solution that has been proposed to this problem is to include in an electric vehicle a power conversion device that is a drive circuit for the electric motor and a charging circuit for the on-board battery. An example of such a power conversion device is disclosed in Chinese utility patent CN 203708127, where use is made of all three of the motor windings of a switched reluctance motor for charging the battery from an AC source. This prior art arrangement is however limited in operation and application. By way of example, it is through its architecture limited to: an AC input for charging; and a switched reluctance motor. Moreover, it is not able to gain the benefits of scale, in that where use is made of multiple motors there is also a need to make use of multiple versions of the conversion device.
Accordingly, there is a need in the art for an improved controller for an inductive load having one or more inductive windings and a controller for such a load.